A metalization stratum or a metalization plane contains a multiplicity of interconnects, for example made of aluminum or copper. Various metalization strata are electrically insulated from one another by a respective insulating layer. The insulating layer is penetrated by “vias” containing connecting sections. In the connecting sections, current flows between various metalization strata during operation of the integrated circuit arrangement.
The intermediate layer is electrically conductive and serves, by way of example, as:
a diffusion barrier,
to increase the mechanical adhesion, and/or
as an antireflection layer.
Suitable materials for the intermediate layer are, by way of example, titanium nitride or tantalum nitride, or double or multiple layers with these materials, e.g. a double layer made of a titanium layer and of a titanium nitride layer.
Typical dry etching processes are:
physical dry etching,
chemical dry etching, or
chemicophysical dry etching.
If the insulating layer is made of silicon dioxide, for example, then dry etching can be carried out using fluorine-containing chemicals, for example.